Stationary induction apparatus



Jan. 18, 1949. G. J. JoHNsToN STATIONARY INDUCTION APPARATUS Filed March 16, 1945 Patented `lan. 18, 1949 STATI ONARY INDUCTION APPARATUS Gorman J. Johnston, Bellevue, Pa., assgnor to Alls-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application March 16, 1945, Serial No. 583,053

9 Claims.

This invention relates in general `to stationary induction apparatus and more particularly to a cooling and ventilating system for encased stationary induction apparatus of the type including,r transformers, reactors and the like.

In prior art systems for encased transformers, vair under pressure has been permitted to flow between the windings in order to provide for a more rapid cooling of the transformer, motor driven fans being used to provide the movement of air. The efficiency of these prior art Cooling systems was limited by the restrictions to the air flow caused by the baille arrangement utilized for directing of the air flow through the windingsI and this was especially true when windings had both Vertical and horizonta-l passageways. The restrictions to air flow found in prior art b'affle arrangements prevented efiicient self-Cooling of the windings when the forced air circulation was not in operation.

It is an object of the present invention to provide an improved cooling and ventilating structure and system in stationary induction apparatus such as transformers and the like, that will avoid the above disadvantages.

It is also an object of the present invention to provide encased electrical apparatus of the above type with bafile means dividing the casing so that an efficient flow of air may be obtained either with natural or forced flow.

It is also an object of the present invention to provide a baflle -arrangement for encased electrical apparatus of the above type which will provide efficient air flow through both longitudinal and lateral passageways between portions of the .windings It is also an object of the present invention to provide a baffle structure for encased electrical apparatus of the above type, which baffle structure is unsymmetrical with respect to the apparatus windings so as to provide a turbulent fiow of air through the lateral passageways in the apparatus.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawing, in which:

Fig. l is a diagrammatic showing of an encased transformer illustrating an embodiment of the present invention Fig. 2 'is a section view taken on the line II-II of Fig. 1; and

Fig. 3 illustrates a modification of the embodiment shown in Figs. 1 and 2.

The invention is illustrated in the drawings in an exemplary manner by a diagrammatic showing of an encased transformer which comprises generally a casing 3 and a core member 4 supported therein by the frame members 25, IS and 19. The windings 5, `8 and 32 are shown as surrounding the core member, the windings 5 and G being illustrative of la divided low voltage winding wound in cylindrical form, and the winding 32 being shown 'as a spaced Stack of disk coils 'l which illustrate a high voltage winding.

The Winding 5 is shown as spaced from the core 4 and the windings 5, -8 and 32 are shown as spaced from each other and from the insulating barrier 2B by means of spacers 20 to provide Vertical or longitudinal passages adjacent each of the wndings. The coils 'l of the winding 32 are spaced by means of spacers 2| to form lateral or horizontal passages therebetween. The core 4 is split into two sections spaced apart by spacers 23 to form a passageway 22 between the two Sections.

The `casing 3 is divided into two portions by means of baflle structure, of a modified Z-shape in cross section and 'composed of elements 8, 9 and IO arranged so that the passa'ge 22 through the core and the passages 'between and adjacent the windings 5, '8 and 32 extend from one portion of the casing to the other. The lower bafile 8 extends from one side of the casing 3 to substantially the center line of the multiple ccres, surrounding the left half of the windings as shown in Figs. 2 and 3, but leaving a passageway 30 between the baille 'and the winding 32. The upper baflle IO extends in a generally similar manner from the right hand side of the casing 3 to the center line of the multiple cores and surrounds the right half of the windings 32, leaving a passageway 3| therebetween. The division of the casing into two portions is completed by Vertical baflles 9 connecting the inner edges of the bafiles 8 and IO where they extend to the center line of the cores. The bafile 9 is spaced from the windings 32 to provide passageways 28.

The lower portion of the casing is provided with openine's Il, |2 and |3 which are shown as protected by louvers 21. The upper portion of the casing is shown as having openings 14 and l5 adjacent which are mounted motor driven fans 16 and ll. Additional openings may be provided in the bottom of the transformer. The portion 24 of the bafile IO is placed at an angle so as to prevent contact with the winding 32, either accidental or otherwise, through the louvers 21 at the opening |3.

The windings 5, G and 32 are symmetrical aesasaz about the longitudinal plane through the multiple cores. By reason of the modified Z-shaped bafiie structure, the fiow of air through the longitudinal and lateral passages is not symmetrial with respect to the longitudinal plane through the multiple cores. With either 'one `or both of the fans M or 55 in operation, air entering the inlets Ii, iii and l flows through the Vertical and horizontal passages in a different manner on the right hand side of the windings than on the left hand side as viewed in Fig. 1. The dissimilarity of air ow on the two sides of the transformer provides a greater turbulence and cross flow than would be provided if .symmetrical air flow was utilized, that is, with baffies and il) both at the top of the coil stack or at the bottom thereof.

On the left hand side of the transformer, the baifle 8 restriots the flow of air so that a relatively small amount passes up around the outside of the winding 32, most of the air fiowing through the Vertical passages, and some of the air from the Vertical duct between the barrier 26 and the winding 32 flowing outwardly through the lateral passages between the coils 'ij On the right hand side 'of the transforiner, thebafiie i being at the top of 'th-e stack, does not restrict the fiow of air entering into the lateral passages between the coils Ti. The flow of air in and through the winding passageways is quite complex and the exact direction of all the air ourrents will depend upon various factors such as the number and positioning of the spacers, the relative size of the various passageways and the thermal differences existing throughout the core and coils. Tests have proved conclusively that the dissirnilar ow of air produced by the modified Z-shaped baflie structure is more efficient than with a straight horizontal cross bafiie providing similar air currents on each side of the transforiner.

` As stated above, the number and positioning of the spacers 2B and 2d aifects the cross flow of air between the coils l'. ln Fig. 2 the spacers and 2| are all shown as positioned 'on the same radial lines but not on a radial line through a longitudinal plane through the center lines of the cores. The cross flow of air in the lateral passages may take 'various paths. As seen from Fig. 2, air may enter the spaces 33 between the coils 'I from the right hand side of the transformer and fiow across the windings to the left hand side. Air may enter the spaces M- and circulate there'in and pass up through the opening 3! or up through the Vertical duct between the barri'er 28 and the winding 32. If the spacers 20 between the winding 33 and the barrier Et do not extend the full length of the Vertical passage, the cross ow of air from the spaces 34 to the spaces 33 and 35 may take place by utilizing the Vertical duct between the barrier 26 and the windings 32 to fiow around the spacers i. The spacers between the winding 32 and the barrier 26 may be positioned only at the ends of the coil stack, or may be omitted if the winding 32 is supported at the outer side thereof. The cross fiow of air also takes place around the outside of the winding 32 through the Vertical passages 28 extending the full length between the Vertical baffie 9 and the Windings 32.

In Fig. 3 the entirestructure is similar to that i'nl'ig.V 2 except for the positioning of the spacers 21. 'These spacers iii are not on the same radial lines as the spacers 2d, but are on the radial line through a longitudinal plane through the center lines of the multiple` cores. In this modification the spaoers 23 between the winding 32 and the barrier 26 may also be full length, partial length, only at the ends of the coil Stack or omitted altogether and, therefore, air fiowing across the winding from the right to the left may utilize the Vertical duct between the. winding 32 and the barrier 2G as a part of the lateral pa'ssage around the spacers Si.

With the fans id and i deenergized, air will flow through the Vertical and horizontal passages due to the fact that the coil stack is hotter at the top than at the b'ottom and the opening E3 may i become an outlet or a partial outlet rather than an inlet. The fiow of air is deoreas'ed With the fans deenergized, however, the circulation of air through the lateral passages will not be restricted as would be the case if the dividing baifle were entirely in one horizontal plane.

Although but two embodiments of the present invention have been illustrated and desoribed, it will be apparent to those skilled in thel art that various changes and niodifications may be made therein without departing from the spirit of the invention or from the scope 'of the appended clairns. l

ft is clairned and desired to secure by Letters Patent:

l. Stationary induction apparatus oomprising a core provided with windings thereon, said windings being spaced to provide lateral and longitudinal passages therebetween, said windings being arra'nged substantially symmetrically about a longitudinal plane through said core and windings, a casing surrounding said core and windings and provided with an inlet in a first portion thereof and an outlet in a second portion thereof for the ilowof Cooling fluid through said passages, and means for separating said first` and second casing portions, said means oomprising a baifle structure having a substantially step-shaped cross section in a plane normal to said longitudinal plane, said baiile structure extending between walls of said casing, whereby the flow of coolingfiuid through said passag'es is dissirnilar on opposite sides of said longitudinal plane.

Stationary induction apparatus comprising a core provided with windings thereon, said windings being spaced to `provide lateral and longitudinal passages therebetween, said windings being arranged substantially syfnnietrically about a longitudinal plane through said core and windings, a casing surrounding said core and windings and provided with an inlet in a rst portion thereof and an Outlet in a second portion thereof, and means for separating said first and second casing portions, said means comprising a baiile structure having a modified Z-shaped cross section in a plane substantially normal to said longitudinal plane.

3. Stationary induction apparatus coinprising a core provided with windings thereon, said windings being spaced to provide lateral and longitudinal passagestherebetween, said windings being arranged substantially syrnmetrically about a longitudinal plane through said core and windings, a vcasing surrounding said core and said windings and provided with an inlet in a first portion thereof and an outlet in a second portion thereof, and a baifle structure having a substantially step-- shaped cross section in a plane normal to said longitudinal plane, said bale structure extending ture in alignment with said longitudinal passages,

aeseaa the edge of said aperture being adjacent said windings whereby said bafiie and said windings cooperate to separate said casing portions, said longitudinal passages providing a rectilinear path for the fiow of cooling fiuid between said casing portions.

4. Stationary induction apparatus comprising a core and windings thereon, a casing surrounding said core and windings, a baffle structure extending between walls of said casing and said windings and dividing said casing into two portions having substantially L-shaped interlocked cross Sections, one of said casing portions being provided with an inlet and the other said casing portion being provided with an Outlet, and means for spacing said windings to form passageways therebetween extending from one to the other of said casing portions.

5. Stationary induction apparatus comprising a core provided with windings thereon, said Windings being arranged substantially symmetrically about a longitudinal plane through said core and windings, a casing surrounding said core and windings and provided with an inlet in a first portion thereof and an Outlet in a second portion thereof, means for separating said first and second casing portions, said means comprising a baffie structure having modified Z-shaped cross section in a plane normal to said longitudinal plane7 and means for spacing said Windings to form. a longitudinal passageway therebetween extending from said first casing portion to said second casing portion and a lateral passageway extending from said longitudinal passageway to said first and second casing portions.

6. Stationary induction apparatus comprising a core provided with windings thereon, said Windings being arranged substantially symmetricaliy about a longitudinal plane through said core and Windings, a casing surrounding said core and windings and provided with an inlet in a first portion thereof and an outlet in a second portion thereof, means for separating said first and second casing portions, said means comprising a baffie structure having a substantially step-shaped cross section in a plane normal to said longtudinal plane, said baflie structure extending betWeen walls of said casing, and means for spacing said windings to form a longitudinal passageway extending from said first casing portion to said second casing portion and a lateral passageway extending from said longitudinal passageway to said first and second casing portions, whereby the fiow of cooling fluid through said lateral passage- Way is dissimilar on opposite sides of said longitudinal plane.

7. Stationary induction apparatus comprising a core provided with Windings thereon, said Windings being arranged substantially symmetrically about a longitudinal plane through said core and windings, a casing surrounding said core and said windings and provided with an inletI in a first portion thereof and an outlet in a second portion thereof, means for spacing said Windings to form a longitudinal passageway therebetween extending from said first casing portion to said second casing portion and a lateral passageway extending from said longitudinal passageway to said first and second casing portions, and a baiile structure having a substantially step-shaped cross section in a plane normal to said longitudnal plane, said baffie structure extending between walls of said casing and having an aperture in alignment with said longitudinal passageway, the edge of said aperture being adjacent said windings, Whereby said bafile and said windings cooperate to separate said casing inlet and Outlet portions, said longitudinal passage forming a rectilinear path for the flow of Cooling fiuid between said casing portions.

8. Stationary induction apparatus comprising a core and windings thereon, a casing surrounding said core and windings, a bafile structure extending between walls of said casing and said Windings and dividing said casing into two portions having substantially L-shaped interlocked crosssections, one of said 'casing portions being provided With an inlet and the other said casing portion being provided With an outlet, and means for spacing said Windings to form a longitudinal passageway therebetween extending from one to the other of said casing portions and a lateral passageway extending from said longitudinal passageway to said casing portions.

9. Stationary induction apparatus to be cooled alternately by natural fiow or forced flow of cooling fiuid, said apparatus comprising a core and windings thereon, a casing surrounding said core and said windings, an inner bafle structure between walls of said casing and said windings and dividing said casing into a lower portion and an upper portion, means for separating said windings to form a passageway therebetween extending from one to the other of said casing portions, the lower part of a wall of said casing lower portion being provided with an inlet and a wall of said casing upper portion being provided With an outlet for the natural fiow of cooling fiuid through said inlet, said passageway and said outlet, the upper part of an outer Wall of said casing defining said lower portion being provided with an aperture, said aperture cooperating with said inlet for the inflow of Cooling fluid circulating by forced fiow through said passageway and said outlet, said aperture cooperating with said outlet for the outflow of Cooling fiuid circulating by natural flow through said inlet and said passage- Way.

GORMAN J. JOHNSTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 694,673 Schwedtmann Mar. 4, 1902 1,523,378 Lennox Jan. 13, 1925 1,563,354 Fortescue Dec. 1, 1925 2,125,138 Vogel July 26, 1938 FOREIGN PA'I'ENTS Number Country Date 167,916 Great Britain Aug. 25, 1921 374,828 Great Britain Dec. 11, 1930 

